I use DirecTv satellite broadband for internet, I plan to finally start playing online multiplayer games on PSN. My problem is because I have satellite broadband I am capped at 450mb download per 24/hr peroid. Will I be downloading huge amounts of data to make me get over my limit or will it be like normal surfing. My unlimited download peroid is between 3:00am to 6:00am which sucks for playing RFOM.

It depends on the game, but most 16-player FPS games work between 3K-10K/second. Multiply that out by how many seconds you plan on playing -- at 3600 seconds, that's a maximum of ~35MB.

However, if your internet access is satellite based, don't even bother. If you're really receiving via satellite (and presumably uploading some other way), you'll have approximately a second of latency, which is about 20x higher than the standard amount of latency gamers expect. This, unfortunately, is due to the speed of light and the distance at which geosynchronous satellites must be.

I'd say that's more or less the upload, the download rate is higher than that, but in any case you should be fine.